Electrocardiography employs the electrical phenomena accompanying the physiological functioning of the heart for diagnostic and other purposes. Electrodes are applied to the chest and extremities of a patient to collect electrocardiographic (ECG) signal data and provide same to an acquisition unit, typically an electrocardiograph or patient monitor. The signals in the electrodes are amplified in a pre-amplifier and are typically displayed on a screen and/or moving paper strip for review and analysis by an attending cardiologist or other clinician. The ECG signal data is also digitized for storage in a memory and for use with computer ECG analysis algorithms.
However, only a limited amount of ECG signal data is often available for use with such acquisition apparatus, such as the data obtained during a single session with the patient. Acquisition apparatus such as a patient monitor, may carry out other tasks or functions besides ECG monitoring. This may limit the computing power available for ECG analysis, necessitating a reduction in a sophistication of an analysis algorithm in the monitor or slowing the analysis process. This limits the type of analysis that can be performed and the thoroughness with which it can be carried out. For example, if real time shape analysis of the heart beat waveforms found in the ECG signal data is desired, this may require transfer of the signal data from the acquisition unit to separate analysis apparatus containing a more sophisticated algorithm. Given the often critical nature of electrocardiological conditions, the limitations and delays attendant the foregoing give rise to the potential for adverse consequences to the patient.
In another example, in a chest pain clinic, a convenient, rapid serial comparison of currently obtained ECG signal data with previously acquired ECG signal data is essential to determine if there has been a change in the cardiac condition of the patient. However, in most cases, the previously acquired ECG signal data is stored in a remote database, such as the central computer for the clinic or hospital. Currently, it is thus often necessary to load the ECG signal data from the cardiograph or patient monitor into different apparatus, such as central clinic or hospital computer, having the database in which the previously acquired ECG signal data is stored. Thereafter, the serial comparison may be run. It will be appreciated that this can be an inconvenient and/or time consuming process, to the detriment to the patient.
To avoid or limit such consequences, rapid, extensive, and thorough ECG analysis is critical to patient welfare. Inconveniences associated with such analyses should be minimized to encourage the use of pertinent algorithms and/or to avoid affecting the accuracy of the ECG data analysis and interpretation, also to prevent detriment to the patient.